Week 5: Parenteral Nutrition Flashcards
(26 cards)
review of terms
- %w/v = grams/100ml
- D5W = 5 g dextrose/100ml
- D70W = 70 g dextrose/100ml
- 10% amino acids = 10 g aa/100ml
- 20% iv fat emulsion = 20 g fat/100ml
- 0.9% sodium chloride = NS or 154 mEq/L
- 0.45% sodium chloride = 1/2 NS or 77 mEq/L
- 0.225% sodium chloride = 1/4 NS or 38.5 meq/L
ASPEN
american society for parenteral and enteral nutrion
1. dieticians, physicians, pharmacists, nurses and other health professionals
2. mission: improve patient care by advancing the science and practice of clinical nutrition and metabolism
3. nutrition support resources for patient and caregivers (JPEN, clinical guidelines, consensus recommendations, standards)
parenteral nutrition
- provision of nutritional requirements via IV
- patient may receive total parenteral nutrition (TPN; all nutrition given IV) or partial (some enteral nutrition)
- commercially available or compounded in pharmacy
- if the gut works use it
PN components
- macronutrients: protein, carbs, fat
- electrolytes
- vitamins, trace elements
- medications
- different doses, products, and considerations for neonates, children and adults
protein
- standard amino acids sol’ns contain essential and nonessential amino acids
- provides 4kcal/gram
- many formulations available (travasol, aminosyn, freamine)
- specialized formulations for pediatrics (trophamine, premasol)
- specialized formulations available for renal/hepatic dysfunctions; expensive and rarely clinically used
carbohydrates
- supplied as dextrose
- provides 3.4kcal/gram
- stepwise titration to goal to allow for appropriate endogenous insulin response
fat
- IV lipid emulsion (ILE) contain fat, glycerol, and phospholipid
- 9 kcal/gram
caloric density of ILE
1. 10% emulsion: 1.1 kcal/ml
2. 20% emulsion: 2 kcal/ml
3. 30% emulsion: 3 kcal/ml
may be
1. plant based (intralipid 20%, clinolipid 20%)
2. fish oil based (omegaven 10%)
3. fish oil and plant based (SMOFlipid 20%)
IV Lipid Emulsion contraindications
- hypersensitivity to soybean - plant based, fish oil snd plant based
- hypersensitivity to egg - plant based, fish oil based, fish oil and plsnt based
- hypersensitivity to fish - fish pil based, fish oil and plant based
- consider calories from additional lipid sources (propofol, clevidipine)
Fat overload syndrome
ILE administration rates exceed the rate of hydrolysis, free fatty acid uptake and clearance
1. usually occurs in accidental overdose
2. always provide ILE infusion ove 24 hours
3. max rate 0.25g/kg/hr (infants/children) and 0.125g/kg/hr (adults)
4. promote ILE clearance; minimize risk
Parenteral Nutrition Associated Liver Disease (PNALD)
hepatic effects of long term PN; can progress to hepatic failure
1. lipid minimization strategies: dose reduction, modified lipid schedule (lipids MWF only), alternate lipid formulation
electrolytes
- sodium, potassium, calcium, magnesium, chloride, acetate, phosphate
- individualized to patient’s needs
- doses may be ordered as individuals ions OR as salts
vitamins
- supplied as commercially available, age appropriate systems
- stability: two vial systems; must be combined for use
- ordered per institutional protocols
- can be modified as clinical situation warrants (phytonadione for hepatic/coagulation disorders or ascorbic acid for wound healing)
trace elements
- copper, zinc, chromium, manganese, selenium
- tailor to patients’ specific needs
- no currently available trace product appropriately addresses trace element needs
other additives/medications
- histamine 2 receptor antagonists (famotidine)
- levocarnitine
- heparin (low dose)
- regular insulin –> adsorbs to PN bag and tubing
- iron dextran
- use trissel’s iv compatibility
tpn formulations
- 2-in-1: combo of dextrose and amino acids, with the lipid emulsion (if needed) piggybacked onto primary IV line
- 3-in-1: combo of dextrose, amino acids and lipids in a single container
total nutrient admixture (TNA)
- 3-in-1
- most stable if concentrations of dextrose > 10%, amino acids > 4%, lipid > 2%
- not typically recommended for use in neonates and infants ( stability and Ca/Phosphate solubility concerns)
creamed emulsion in TNA
can be made homogenous by gently inverting the bag several times; safe to administer to a patient
cracked emulsion in TNA
cannot be made homogenous; unsafe to administer
PN administration
may be infused continuously over 24 hours or cycled
cycled TPN
- convenient for home use
- more closely mimics enteral feeding
- allows for post-absorptive state
- may avoid some metabolic complications of long term TPN
- attempted only after patient is clinically and metabolically stable, TPN > 7 days
role of the pharmacist
clinical nutritional considerations
1. fluid and caloric requirements
2. electrolyte needs; acid/base status
3. managing complications
4. growth (neonates/children)
compounding considerations
1. calcium phosphate precipitation
2. ion balancing
3. ingredient volumes
4. osmolarity limitations
calcium phosphate precipitation influenced by
- ca and phosphate dose/concentration
- calcium salts: gluconate preferred over chloride
- pH/amino acid concentration: lower pH (higher amino acid concentration) improves ca/phos solubility
- order of ca and phos addition: add phos first. separate ca and phos containing ingredients during administration
- temperature: increased temperature increases likelihood of precipitation
- storage time: increased storage time increases likelihood of precipitation
peripheral line for PN
- max osmolarity 900 mOsm/L
- max dextrose concentration 10-12.5% (limits calories)
- limits to calcium concentration (vesicant)
central line
- ideal for long term PN
- allows for higher dextrose concentration (increased calories)
